I want to cancel my train ticket YCYZRN and get a refund

My ticket is depart from Rome to Milano Centrale at 17th Sept 2015 19:20. The reason why I want to cancel this is because I booked wrong date and I took the train when I wanted and paid the ticket price on the train. i know there is penalty of refund and it is okay for me so please refund the money as soon as possible anx please contact me by email if you have any further questions or answer. My ticket detail is my name is Dae Min Jung and I booked super economic for 1 Adult. My email address is jdm91zzing@naver.com.